The 42 amino acid Alzheimer's Aߠpeptide is involved in the progression of Alzheimer's disease. Here we describe the effects of intracellular A߬ produced through its attachment to either end of a green fluorescent protein, in yeast. Cells producing Aߠexhibited a lower growth yield and a heat shock response, showing that Aߠfusions promote stress in cells and supporting the notion that intracellular Aߠis a toxic molecule. These studies have relevance in understanding the role of Aߠin the death of neuronal cells, and indicate that yeast may be a new tractable model system for the screening for inhibitors of the stress caused by A߮